Voice

Singing, or the human voice, is the primordial musical instrument, characterized by being a physiological and non-manufactured structure. Morphologically, this "instrument" is divided into three interdependent systems: the motor (lungs and diaphragm, which provide air pressure), the oscillator (the vocal folds, located in the larynx), and the resonator (the vocal tract, which includes the pharynx, the oral cavity, and the nasal cavity).

Acoustically, sound production (phonation) occurs when the pulmonary airflow forces its way through the approximated vocal folds, causing them to vibrate. The fundamental glottal sound, initially weak and complex, is projected into the vocal tract. Here, the articulators (tongue, lips, soft palate) dynamically alter the shape of the resonance cavities, amplifying specific frequencies (the formants) and thus defining the vowels, consonants, and the singer's individual timbre.

Historically, being intrinsic to human beings, the voice precedes any physical instrument. In Western music, the technical systematization of singing developed profoundly with the advent of opera at the end of the 16th century. The Italian school of bel canto, consolidated between the 17th and 19th centuries, established the pedagogical standard of agility, homogeneity of registers, and acoustic projection that still governs lyrical singing.